Crown thioether chemistry. Synthesis and structural investigation of 1,5,9-trithiacyclododecane (trithia-12-crown-3) and its copper(II) chloride adduct

Abstract

1,5,9-Trithiacyclododecane (L¹)(trithia-12-crown-3) adopts a square conformation similar to that of cyclododecane, with one sulphur atom at a corner and two in side positions. Reaction with copper(II) chloride yields an adduct, [Cu(L¹)₂Cl₂], that has been characterized by X-ray diffraction. Each copper ion occupies a centre of inversion and has idealized octahedral microsymmetry, with thioether groups at distances of 2.447(1) and 3.050(1)Å. The conformation adopted by the macrocycle is virtually identical to that adopted by the free ligand, which suggests that its conformation is determined by intrinsic factors rather than packing forces.